Airhammer construction

ABSTRACT

This invention relates to an airhammer, the barrel of which is constructed by assembling in axial registration a plurality of stamped discs, each held in axial registration by a pair of aligning rods, and each provided with complementary apertures which define the necessary air passages and piston chamber.

United States Patent lnventor Lowell N. Brown 11612 Bowling Green, St.Louis County, Mo. 63141 Appl. No. 54,892

Filed July 15, 1970 Patented Nov. 16, 1971 AIRHAMMER CONSTRUCTION 8Claims, 2 Drawing Flgs.

US. Cl 173/136. 173/169.173/171. 310/50 lnt.Cl 1323b 45/04 FieldolSearch 1. 173/134,

[56] References Cited UNITED STATES PATENTS 1,245,860 11/1917 Black etal. 173/170 2,512,763 6/19 50 Bergmann 173/134 Primary Examiner -JamesA. Leppink Attorney-Joseph A. Fenlon, Jr.

ABSTRACT: This invention relates to an airhammer. the barrel ofwhich isconstructed by assembling in axial registration a plurality of stampeddiscs. each held in axial registration by a pair of aligning rods, andeach provided with complementary apertures which define the necessaryair passages and piston chamber.

PATENTEDnnv 1s lBIl SHEEI 1 0F 2 4 FIG. 6

INVENTOR LOWELL N BROWN OL FW ATTY PATENTEUuuv 16 I97! 3,620,131 1 sum 20F 2 2 INVENTOR LOWELL N BROWN ATTY AIRHAMMER CONSTRUCTION It is theobject of this invention to provide a new construction for an airhammerbarrel which provides for selectively variable barrel lengths, andinexpensive construction and as sembly.

With the above and other objects in view, which will become immediatelyapparent upon reading the specifications, my invention resides in theunique and novel form, ar rangement, construction and combination ofparts shown in the drawings, explained in the specifications, andclaimed in the claims.

In the drawings:

FIG. 1 is a side elevational view of a preferred embodiment of myinvention.

FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1;

F IG. 3 is a fragmentary sectional view taken along lines 3- 3 of FIG.2;

FIG. 4 is an enlarged front view of a barrel disc;

FIG. 5 is an enlarged front view of an external exhaust disc;

and

FIG. 6 is an enlarged front view of an internal exhaust disc. Referringnow in more detail and by reference characters to the drawings, whichillustrate a preferred embodiment of my invention A designates anairhammer comprising a handle 10, a barrel 12 in which a piston 14 isslidably mounted, and a tool attachment end 16. The handle includes atrigger valve 18 which, upon depression, supplies air under pressure tothe bar rel 12 through an air passage 20. The tool attachment end 16comprises an annular sleeve 22 threaded externally to receive aconventional tool-attachment device (not shown) and provided on itsinner face with two inwardly presented threaded bores 24, 26, ineach ofwhich is inserted an end of one of a pair of elongated aligning rods 28,30, all for purposes presently more fully to appear.

The barrel 12 comprises a plurality of substantially identical corediscs 32, a centrally located external exhaust disc 34, and an internalexhaust disc 36, all stacked in axial registration.

Each disc 32 is provided with a pair of diametrally separated alignmentbores 38, 40; a pair of smaller, diametrally separated channel bores 42,44; and a larger center bore 46. Similarly, each disc 34, is providedwith a pair of diametrally separated alignment bores 48, 50; a pair ofsmaller, diametrally separated channel bores 52, 54; and a larger centerbore 56. Also, each disc 36 is provided with a pair of diametrallyseparated alignment bores 58, 60; a pair of smaller diametrallyseparated channel bores 62, 64; and a larger center bore 66. In theexternal exhaust disc 34, an exhaust passageway 68 providescommunication between the center bore 56 and the outer periphery of thedisc 34. In the internal exhaust disc 36, a pair of internal exhaustpassageways 70, 72 provide communication between the channel bores 62,64, respectively and the center bore 66. The alignment bores 38, 48 and58 are each sized for receiving snugly the aligning rod 28, andsimilarly the alignment bores 40, 50 and 60 are each sized for receivingsnugly the aligning rod 30. The channel bores 42, 52 and 62 are locatedin such manner that when the discs 32, 34 and 36 are disposed on thealigning rods 28, 30, a continuous air passage 74 is defined by thosebores which extend axially along the barrel l2, and similarly thechannel bores 44, 54 and 64 are located to define a second continuousair passage 76 which also extends axially along the barrel 12. Alsosimilarly, the center bores 46, 56 and 66 define a continuous pistonchamber 78 in which the piston 14 can be moved when the discs 32, 34 and36 are disposed on the aligning rods 28, 30. As can be seen by thedrawings, the barrel 12 comprises a plurality of stacked discs 32, acentrally located external exhaust disc 34, and an internal exhaust disc36 located at the outer end of the barrel l2. Disposed on the aligningrods 28, at the inner end of the barrel 12 is a conventional fluttervalve 80 including a center port 82 in communication with the pistonchamber 78,'a first return port 84 in communication with the air passage74, a second return port 86 in communication with the air passage 76,and an inlet port 88 in communication with the conventional triggervalve 18 which supplies air under pressure to the flutter valve uponactivation. As can be seen from the drawings, the aligning rods 28, 30extend through the handle 10 and the hammer A is held in the assembledcondition by nuts 92, 94 which are secured to the ends of the aligningrods 28, 30.

The operation of the hammer A is conventional. When the piston 14 islocated outwardly of the disc 34, the flutter valve senses the decreasein pressure behind the piston 14 and supplies air to the return passages74, 76, which passes into the piston chamber 78 forwardly of the piston14 through the internal exhaust passageways 70, 72 and urges the piston14 to the back of the chamber 78. As the piston passes back past thedisc 34, the flutter valve senses the decrease in pressure forwardly ofthe piston 14 and the flutter valve shifts the pressurized air to thecenter port 82 and into the rear of the chamber 78 which propels thepiston 14 against the tool (not shown), being held in thetool-attachment end 16.

The uniqueness and novelty in my invention is not in the creation of anairhammer per se, but rather in the creation of an airhammer which maybe assembled using conventionally stamped parts, as opposed to the morecomplex and expensive castings. The utilization of the discs 32, 34 and36 to fabricate the barrel 12 not only reduces the cost and simplifiesthe procedures of manufacture, but also permits the use of the sameparts to provide a multiplicity of hammers of varying lengths using saidsame parts.

It should be understood that changes, alterations and modifications inthe form, construction, arrangement, combination of various parts of myinvention hereinshown may be made and substituted without departing fromthe nature and principle of my invention.

Having thus described my invention what I claim and desire to secure byLetters Patent is recited in the specifications, shown in the drawingsand claimed in the claims.

1. An airhammer comprising a barrel, a toolholder attached to one end ofthe barrel, and a handle attached to the other end of the barrel andincluding a flutter valve and trigger means for selectively supplyingair under pressure to the flutter valve said barrel comprising aplurality of first discs each provided with a first center bore and alsoprovided with a first intermediate bore, a second disc provided with asecond center and a second intermediate bore and an external exhaustpassageway establishing communication between the second center bore andthe periphery of the second disc; a third disc provided with a thirdcenter and a third intermediate bore and an internal exhaust passagewayestablishing communication between the third intermediate bore and thethird center bore, said first, second and third discs being stacked inregistration in such manner that their respective center bores define acontinuous center chamber between the toolholder and the flutter valveand their respective outer bores define a continuous intermediatechamber between the toolholder and the flutter valve, said third discbeing located near the toolholder and said second disc being located insubstantially the center of the stacked discs, said flutter valveincluding a center port in communication with the center chamber and areturn port in communication with the intermediate chamber, a pistonmovably mounted in the center chamber between the toolholder and theflutter valve, and securing means for bolding the discs and the fluttervalve in aligned registration between the toolholder and the handle.

2. The device of claim 1 in which the first, second and third discs areannular.

3. The device of claim 1 in which the securing means includes analignment rod secured at one end to the toolholder and at the other endto the handle, and which projects through, in snug-fitting disposition,alignment bores located in each of the three types of discs.

4. The device of claim 1 in which each of the discs is annular andsubstantially smaller in thickness than in diameter, and in which thevast majority of discs used to construct the barrel comprises firstdiscs.

5. A barrel for an airhammer including a tool-attachment device and ahandle, said barrel comprising an elongated stack of waferlike discswhich are assembled in face-to-face registratron,

an elongated piston chamber extending longitudinally along the stack andwhich is defined an aperture in each of said discs,

an air passageway extending longitudinally from the handle end of thebarrel to the tool-attachment device end of the barrel and which isdefined by a bore located in each of said discs,

a first port located near the tool-attachment device end of the barrelwhich establishes air communication between the piston chamber and theair passageway,

a second port located near the center of the barrel which establishesair communication between the piston chamber and the outside atmospherewhereby to provide an exhaust outlet for the piston chamber, a pistonmovably disposed in the piston chamber, valve means for alternatelyproviding air under pressure to the front and back portions of thepiston for driving the piston backwardly and forwardly respectively pastthe second port, and means for holding the discs in such face-to-faceregistration and for simultaneously securing the tool-attachment deviceand the handle to the stack of discs and the valve means. 6. The deviceof claim 5 wherein the discs are annular. 7. The device of claim 5wherein the first port is integrally included in one of the discs.

8. The device of claim 5 wherein the second port is integrally includedin one of the discs.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,20,311 Dated November 16, 1971 Inventor(s) L N 3:

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

On the cover sheet, [54] under the title ,AIB AM R CONSTRUCTION, "8Claims, 2 Drawing Figs." should read 8 Claims, 6 Drawing Figs. Column 2,line 41, after "valve" insert a comma. Column 3, line 6, after "defined"insert Signed and sealed this 31st day of October 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents )RM PC4050 (0459) uscoMM-oc cove-pee ,5. GOVERNMENT PRINTINGOFF|CE1 I," Q J."JJI.

1. An airhammer comprising a barrel, a toolholder attached to one end ofthe barrel, and a handle attached to the other end of the barrel andincluding a flutter valve and trigger means for selectively supplyingair under pressure to the flutter valve said barrel comprising aplurality of first discs each provided with a first center bore and alsoprovided with a first intermediate bore, a second disc provided with asecond center and a second intermediate bore and an external exhaustpassageway establishing communication between the second center bore andthe periphery of the second disc; a third disc provided with a thirdcenter and a third intermediate bore and an internal exhaust passagewayestablishing communication between the third intermediate bore and thethird center bore, said first, second and third discs being stacked inregistration in such manner that their respective center bores define acontinuous center chamber between the toolholder and the flutter valveand their respective outer bores define a continuous intermediatechamber between the toolholder and the flutter valve, said third discbeing located near the toolholder anD said second disc being located insubstantially the center of the stacked discs, said flutter valveincluding a center port in communication with the center chamber and areturn port in communication with the intermediate chamber, a pistonmovably mounted in the center chamber between the toolholder and theflutter valve, and securing means for holding the discs and the fluttervalve in aligned registration between the toolholder and the handle. 2.The device of claim 1 in which the first, second and third discs areannular.
 3. The device of claim 1 in which the securing means includesan alignment rod secured at one end to the toolholder and at the otherend to the handle, and which projects through, in snug-fittingdisposition, alignment bores located in each of the three types ofdiscs.
 4. The device of claim 1 in which each of the discs is annularand substantially smaller in thickness than in diameter, and in whichthe vast majority of discs used to construct the barrel comprises firstdiscs.
 5. A barrel for an airhammer including a tool-attachment deviceand a handle, said barrel comprising an elongated stack of waferlikediscs which are assembled in face-to-face registration, an elongatedpiston chamber extending longitudinally along the stack and which isdefined an aperture in each of said discs, an air passageway extendinglongitudinally from the handle end of the barrel to the tool-attachmentdevice end of the barrel and which is defined by a bore located in eachof said discs, a first port located near the tool-attachment device endof the barrel which establishes air communication between the pistonchamber and the air passageway, a second port located near the center ofthe barrel which establishes air communication between the pistonchamber and the outside atmosphere whereby to provide an exhaust outletfor the piston chamber, a piston movably disposed in the piston chamber,valve means for alternately providing air under pressure to the frontand back portions of the piston for driving the piston backwardly andforwardly respectively past the second port, and means for holding thediscs in such face-to-face registration and for simultaneously securingthe tool-attachment device and the handle to the stack of discs and thevalve means.
 6. The device of claim 5 wherein the discs are annular. 7.The device of claim 5 wherein the first port is integrally included inone of the discs.
 8. The device of claim 5 wherein the second port isintegrally included in one of the discs.